My default answer would probably be Batman Begins, just because I've always felt that The Dark Knight was less a Batman movie and more of an urban drama with Gotham characters in it. The first one had more of a style to it that I've always admired, despite both being incredibly well made and well done movies.

My feelings entirely. Also, Gotham progressively loses its atmosphere as the movies go on. By the time we get to TDKR, it's totally white-washed and has no personality of its own.